Fuel injection apparatus



Aug. 28, 1962 A. R. SCHOLIN 3,051,087

FUEL INJECTION APPARATUS Filed Dec. 14, 1959 5 Sheets-Sheet 1 INVENTOR.AXEL R. SCHOLIN Aug. 28, 1962 A. R. SCHOLIN 3,051,087

FUEL INJECTION APPARATUS Filed D90. 14, 1959 5 Sheets-Sheet 2 NINVENTOR.

LL AXEL R. SCHOLIN ATTY.

Aug. 28, 1962 A. R. SCHOLIN FUEL INJECTION APPARATUS 5 Sheets-Sheet 4Filed Dec. 14, 1959 INVENTOR. Axau. R. SCHOLIN ATTY.

Aug. 28, 1962 A. R. SCHOLIN 3,051,087

FUEL INJECTION APPARATUS Filed Dec. 14, 1959 5 SheetsSheet 5 INVENTOR.AxEL. R. SCHOLIN ATTY.

United States Patent 3,051,087 FUEL INJECTION APPARATUS Axel R- Scholin,4646 N. Wolcott Ave., Chicago 40, Ill. Filed Dec. 14, 1959, Ser. No.859,484 4 Claims. (Cl. 1034) The present invention relates to fuelinjection apparatus for delivering in a controllable manner highpressure fluid such as liquid diesel oil in the case of diesel engines,or gasoline in the case of combustion engines having electrical ignitionsystems.

It is among the general objects of the present invention to provide animproved fuel injection apparatus for delivering a fluid, specifically aliquid, to separate points from a source of the liquid, with the fluidbeing maintained at a substantially constant pressure at such deliverypoints during the delivery thereof.

A further object of the invention is to provide an apparatus of thissort which is adaptable, with no modification whatsoever, to use inconnection with internal combustion engines having the same number ofengine cylinders, regardless of the disposition of such cylinders, i.e.whether the engine be of the in-line type or a V-type engine.

A still further object of the invention is to provide such a fuelinjection apparatus including a series of injection pumps of thereciprocable plunger, cam-operated type and which embodies novel meansfor either individually or collectively controlling the effective strokeof the plungers associated with the various pumps. By individuallyadjusting the stroke of the plungers, it is possible to regulate thequantity of fuel fed to each cylinder so that at any given engine speedequal quantities of fuel will be delivered at equal pressures to all ofthe cylinders. By collectively adjusting the stroke of the plungers,throttle operation of the engine is made possible in such a manner thatduring each engine cycle i.e. upon one complete revolution of the enginecrankshaft, equal quantities of fuel will be delivered to all of thecylinders in the proper order of timing and in amounts commensurate withany desired engine speed.

Fuel injection devices which depend for their operation upon a series ofinjection pumps of the reciprocable plunger type and in which theplungers are operated by means of rocker arms under the control of acommon cam shaft are known and conventional devices of this characterare difficult to mount and, furthermore, interchanging thereof isextremely diflicult. Most of these devices must be designed for a giventype of engine and they are incapable of servicing other types ofengines. The adjustments required of such devices are involved and theyrequire considerable time and skill, even when they are preformed bytrained experts in the field. Most of these devices are designed ascomponent parts of the engine itself and, when the engines are of themotor vehicle type, servicing or replacement of the devices can be madeonly by skilled labor and in specially equipped workshops to which thevehicle must be brought.

The present invention is designed to overcome the above-notedlimitations that are attendant upon the use of conventional fuelinjection apparatus and systems of this character and, toward this end,it contemplates the provision of a novel form of injection apparatuswhich may readily be mounted on a vehicle and operatively connected tothe combustion engine thereof by the ordinary mechanic or other operatorand which, when once mounted, may readily be serviced in the fieldwithout necessitating shop servicing. The invention further contemplatesthe provision of such an apparatus which, for major servicing, mayconveniently be removed from the 3,051,087 Patented Aug.28, 1962 "icevehicle, taken to the shop, repaired and reassembled in the vehicle witha minimum of time and labor consumed.

The provision of an apparatus of the character briefly outlined abovebeing among the principal objects of the invention, yet another objectis to provide an injection apparatus of the rocker-operated,reciprocable plunger type wherein the various rocker arms for operatingthe plungers may, by the simple expedient of loosening a singlefastening screw, be moved to an out-of-the-way position wherein theupper ends of the plungers are exposed and readily accessible forremoval by merely pulling them from the guide sleeves in which theyoperate. By such an arrangement, replacement of worn plungers may beeffected with little difficulty.

Another object of the invention in a rocker operated multiple pumpassembly is to provide an extremely effective novel lubrication systemwherein lubricant is supplied to all of the working moving parts of theassembly in adequate amounts while an excess of lubricant isautomatically supplied to certain strategic locations where frictionalforces would otherwise be excessive.

Yet another object of the invention is to provide a fuel injectionapparatus embodying a series of fuel pumps of the reciprocable plungertype having associated therewith novel means whereby any pump leakagecaused by the bypassing of fuel around the reciprocating pistons will beeffectively discharged from the pump cylinders so that this leakagefluid will not cause binding of the plunger or otherwise interfere withproper plunger operation.

An important and specific object of the present invention, in a fuelinjection apparatus for internal combustion engines, is to provide amultiple pump system including a pump individual to each engine cylinderand wherein all of the pumps are of the reciprocable plunger type inwhich the plunger operates within a cylinder or bore having a fuel inletopening in the wall thereof adapted to be cut off by passage of theplunger thereacross. In further fulfilling this object novel means areprovided for collectively varying, not the amplitudeof the strokes ofthe various plungers as is customary with many conventional fuelinjection systems, but the level at which the various pistons operatewithin their respective bores, thus not only advancing or retarding theactual time of cut-off, but also varying the quantity of fuelpressurized and delivered to the cylinders during the time the plungersmove from the points of cut-oif to the limit of their downward stroke.

The provision of a fuel injection apparatus which is extremely simple inits construction; one which is comprised of a minimum number of parts,particularly moving parts, and which therefore is unlikely to get out oforder; one which is rugged and durable and which therefor is not subjectto undue wear; one which will accommodate a high range of fueldisplacement; one which is small and compact considering its capacity;and one which, otherwise, is well adapted to perform the servicesrequired of it, are further desirable features which have been home inmind in the production and development of the present invention.

Numerous other objects and advantages of the invention, not at this timeenumerated, will become readily apparent as the following descriptionensues.

In the accompanying five sheets of drawings forming a part of thisspecification one illustrative and preferred embodiment of the inventionhas been shown.

In these drawings:

FIG. 1 is a side elevational View of an automotive internal combustionengine showing the fuel injection apparatus of the present inventionoperatively applied thereto;

FIG. 2 is an enlarged fragmentary sectional view taken verticallythrough a portion of a fuel injection apparatus of FIG. 1 in thevicinity of one of a number of injection pumps employed in connectionwith the present invention;

FIG. 3 is an exploded view, partly in section, illustrating thetelescopic assembly of certain pump elements associated with each pumpassembly;

FIG. 4 is a top plan View of the structure shown in FIG. 2;

FIG. 5 is a fragmentary sectional view similar to FIG. 2 showing theparts in a different position;

FIG. 6 is a reduced sectional view taken substantially along the line6-6 of FIG. 5 with certain rocker arm mechanism omitted in the interestsof clarity;

FIG. 7 is a sectional view taken substantially along the line 77 of FIG.4;

FIG. 8 is a fragmentary side elevational view of the structure shown inFIG. 4;

FIG. 9 is a fragmentary sectional view taken substantially along theline 9-9 of FIG. 4; and

FIG. 10 is a sectional view taken substantially along the line 10-10 ofFIG. 9'.

General Considerations Referring now to the drawings in detail and inparticular to FIG. 1, the fuel injection system of the present inventionis shown as being operatively embodied in a composite iluid deliveryapparatus or assembly which is' designated in its entirety at 10 and itis adapted to provide fluid such as diesel oil, in the case of a dieseltype internal combustion engine, or gasoline in the case of a combustionengine having provision for timed electrical ignition, through a seriesof fuel lines 12 leading from a common fuel reservoir 14 to a series ofindividually connected injectors or nozzles 16 by successive pulsingoperations under the control of a series of pump assemblies 17 therebeing one assembly for each fuel line 12 and its respective nozzle 16.The nozzles 16 are shown in FIGS. 1 and 5 as being operatively connectedto the intake manifold 18 of the combustion engine 20, it beingunderstood of course that the point of introduction of fuel into themanifold 18 for each nozzle 16 will be in the immediate vicinity of theintake valve for the particular cylinder supplied by such nozzle. Thepoints of delivery of fuel to the various engine cylinders will vary fordifferent types of combustion engines and the fuel lines 12, being inthe form of conventional copper tubing, may be appropriately cut tolength and shaped so that they may be attached by appropriate fittingssuch as the fittings 21 and 22 for straight line or V-type cylinderarrangements so that no modification of the appartus 10 is required toaccommodate the delivery of fuel to the desired regions.

Pressurization and discharge of the fuel is accomplished byreciprocation of a series of plungers 24 associated with the variouspump assemblies 17, and descent of each piston closes off a series offuel inlet openings 26 leading from the fuel reservoir 14 to a fuelpressurizing and displacement chamber 28 with subsequent compression ofthe fuel below the chamber to the point where the resistance of acompression spring 30 is overcome so that fuel is caused to pass arounda valve element 32 and in the form of a solid column through the fuelline 12 to the corresponding injection nozzle 16. Each plunger 24 isoperable under the control of a rocker arm 33 which, in turn, isoperable under the control of a cam 34. The various rocker arms 32 aremounted for rocking movement on a shaft 36 and the latter is capable ofbeing shifted or displaced in a transverse direction in such a mannerthat the effective stroke of the various plungers 24 may be varied tovary the quantities of fuel displaced by the various plungers duringeach stroke thereof. The cams which actuate the rocker arms are drivenin timed relation to the engine crankshaft and the cams are so adjustedthat each plunger will displace fuel for fuel pressurization andtransmission to the intake manifold for delivery to its respected enginecylinder at the precise time that the intake valve for that cylindercommences to open as is customary withfuel injection systems of thisgeneral character. The displacement of the rocker arm shaft is effectedunder the control of a lever 38 which, upon depression thereof causesthe rock shaft 36 to be lowered so that the effective strokes. of thevarious rocker arms 33 will likewise be varied. When applied toautomotive use, the control lever 38 will be operatively connected to anarticulated motion-transmitting train to a manual or foot pedal such asthe accelerator pedal of the vehicle so that the quantity of fuel fed tothe engine will predetermine the rpm. of the vehicle.

From the above brief description it will be seen that the invention ispredicated upon the use of variable displacement pumps for supplyingfuel to the various engine cylinders, each pump including a reciprocableplunger which, upon descent thereof, establishes a cut-01f for theopening leading to the pressurization chamber. Because the cams whichcontrol the reciprocation of the plungers are constant displacementcams, the actual stroke of the plungers within their respective pumpcylinders does not vary in amplitude, but the range of movement of theplunger is shifted as the common shaft on which the rocker arms aremounted for tilting movement is shifted vertically in one direction orthe other. With the plunger reciprocating at a given amplitude through ahigh range of movement within the cylinder, movement of the plunger pastthe cut-off point will be slight so that a relatively small quantity offuel will be pressurized in and displaced from the pressure chamber andthus fed to the injection nozzle. With the plunger reciprocating at alower range Within the pump cylinder but with the same amplitude, thecutoff point will be reached earlier in the cycle so that the balance ofthe downward stroke of the plunger thereafter will displace a greaterquantity of fuel. Such is the essence of the present invention. Thespecific details of the structure which has been illustrated herein forcarrying out these principles of the invention are merely exemplary andthey will now be described in considerable detail, together with certainother refinements associated therewith as, for example, a novel splashlubrication system employed for maintaining the working parts of thesystem adequately lubricated.

The Casing and Framework Structure Referring now to FIGS. 5 and 6 thefuel injection assembly 10 briefly described above involves in itsgeneral organization a main body or casing 40 of generally cupshaperectangular design and including a substantially flat bottom wall 42,side walls 44 and 46 respectively, and front and rear end walls 48 and50 respectively. The casing 40 is adapted to be fixedly secured in anysuitable manner, either directly to a portion of the engine block 51 orto a portion of the vehicle chassis 554, the casing 40 bring illustratedherein as being mounted on a horizontal member 56 suitably supported onthe chassis.

The upper end of the casing 40 is open but is maintained normally closedby means of a suitable cover plate 52 which is lbolted as at 54 to theflanged upper rim 56 of the casing, a suitable gasket 58 beinginterposed between the cover plate 52 and rim 56. The cover plate 52 isformed with a pair of depending oil-collecting and distributing ribs 60and 62 respectively, the nature and function of which will be made clearpresently; A filling opening 64 is provided in the cover plate 52 and isadapted to be closed by a closure plug 66. A drain plug 67 is providedfor the casing bottom wall 42.

The side wall 44 is provided with a thickened portion or section 70defining an upwardly facing shelf or ledge 71 and this thickened portionof the side wall is extended downwardly as at 72 (see also FIG. 5)beyond the level of the bottom wall 42 of the casing 40. A series ofvertical bores 74 are drilled through the thickened part 70 of the wall44 and the various pump assemblies so that the fuel inlet opening to thepressurizing chamber 28 will be cut off almost at the commencement ofeach downward stroke of the plunger 24 and the plunger will force thesolid column of liquid in the chamber 23, bore 120 and tubing 12 agreater distance after the end of the plunger has passed the cut-offpoint with respect to the opening 26 so that an appreciably greaterquantity of fuel will be fed through the injection device 16. It will beunderstood of course that intermediate adjustments of the shaft 36between the uppermost and lowermost positions of which it is capable ofassuming will result in proportionate displacements of fuel and thefeeding of proportionate volumes of fuel through the injection device 16to the intake manifold 18.

The Rocker Arm Assemblies Referring now to FIGS. 2 and 4, the shaft 36on which the rocker arms 33 are mounted has its ends fixedly secured tothe distal ends respectively of a pair of lever arms 160 which arecapable of limited oscillatory movement about the aXis of a pair ofstuds 162 which are threadedly received in the front and rear end walls48 and 50 respectively of the casing 44). Clamping nuts 164 serve toclamp the distal end regions of the lever arms 160 against respectiveshoulder 166 provided near the opposite ends of the shaft 36. The twolever arms 160, together with the shafts 36, constitute in effect arigid U-shaped frame-like structure of which the shafts 36 constitutethe bight portion, and which bight portion is capable of limitedmovement throughout a very small arc tangent to a vertical plane. Theindividual rocker arms 33 have enlarged central portions 170 providedwith spacer bosses 172 on opposite sides of the arm, the shaft 36extending through the spacer bosses, and the latter serving to maintainthe rocker arms 33 in their spaced relationship along the shaft 36 withlittle or no side play between these rocker arms.

One end of each rocker arm 33 is bifurcated as at 174 and a pin 176extends between the two bifurcations. A roller 178 is mounted on the pinand this roller constitutes a cam follower for the adjacent cam 34 whichit overlies. The other end of the rocker arm 33 carries an adjustingscrew 180 which is threadedly received in the arm and is adapted to beclamped in any desired position of adjustment by means of a clamping nut182. The head portion of the adjusting screw 180 is provided with ahardened semi-spherical bearing surface 183 designed for engagement withthe extreme upper end of the adjacent plunger 24 of the respective pumpassembly 17.

(The Rocker Arm Adjusting Mechanism) Still referring to FIGS. 2 and 4and additionally to FIGS. and 6, the means for collectively adjustingthe position of the various rocker arms 33 comprises a manually orpedally operable rock shaft 190, the rear end of which is rotatablysupported in an anti-friction hearing assembly 192 carried by the rearend wall 50 and the other end region of which is rotatably supported ina similar bearing assembly 194, with the shaft projecting completelythrough this latter bearing assembly. An adjustment foot 196 has abifurcated end 198 adapted to be adjustably clamped by a screw to thefront end of the shaft 190 and the distal end of the foot 196 isdesigned for cooperation with a limit stop screw 202 (FIGS. 4 and 5)which is threaded through the horizontally turned end 204 of an L-shapedbracket 206 which is clamped by means of 6 screws 208 in a verticalposition to the front end wall 48 of the casing 140.

Mounted upon the rock shaft 190 adjacent the ends of the shaft andwithin the confines of the end walls 48 and are a pair of collars 210each of which is formed with a radially projecting finger 212 adapted toproject between a pair of bifurcations 214 provided at the extremedistal ends of the lever arms 160. The rear end of the rock shaft 190projects completely through the bearing 192 and is adapted to haveclamped thereto by means of a clamp- Cir ing screw 216 the split end 218of the previously vertical operating lever 38. The distal end of thelever 220 is provided with an attachment hole 222 therethrough by meansof which this lever may, through the medium of a suitable linkagemechanism or the like (not shown) be operative ly connected to a footpedal which may constitute the accelerator pedal of the vehicle which ispropelled by the combustion engine.

The various rocker arms 33 are mounted for free and independent rockingmovement on the shaft 36 and the cam followers 73 are normallymaintained in rolling contact with their respective cams 34 under theinfluence of the springs 134 which normally urge the plungers 24upwardly to their fully retracted positions. The springs 134 thereforenot only serve to maintain the plungers 24 elevated but they also serveto apply yieldable torque to the rocker arms 33 tending to rotate themin a clockwise direction as viewed in FIG. 2 so that the cam followers178 will rest upon the cams 34 and, by a second class lever action,normally urge the shaft 36 on which the rocker arms 33 are mounted in anupward direction, to in turn urge the supporting levers 164 of the shaft36 to swing in a clockwise direction about the axis of the studs 162.These latter levers 16!) will in turn, through the medium of thebifurcations 214 bearing against the fingers 212 serve to urge thecollars 210, and consequently the rock shaft 1% in a counterclockwisedirection so that the distal end of the lever 38 will be raised to thefullest extent of which it is capable, the final position of the leverbeing determined by the setting of the adjusting screw 202' (FIG.

From the above description it will be seen that upon depression of thelever 38, the rock shaft will be turned in a clockwise direction asviewed in FIG. 2, so that under the influence of the fingers 212provided on the collars 210, the bifurcated distal ends 214 of the twolever arms 16d will be lowered, thus carrying with them the shaft 36 onwhich the various rocker arms 33 are mounted. Since the cams 34 are notadjustable about their common axis of rotation, the net effect of thelowering of the shaft 36 will be to cause the operating ends of therocker arms 33 to oscillate at the same amplitude of displacement but ina lower region wherein the plungers 24 are caused similarly toreciprocate at the same amplitude but with an earlier cut-off aspreviously described.

The Cam Shaft and Its Driving Mechanism Referring now to FIGS. 1, 4 and7, the various cams 34 are preferably circular in contour and thecylindrical operating surfaces thereof have their centers offset fromthe longitudinal axis of the cam shaft upon which they are mounted. Thiscam shaft is shown at 233 and each of the cams 34 is formed with asleeve portion 232 through which there extends a pair of set screws 234by means of which the angular position of the cam 34 ion the shaft 233may be adjusted and the cam thereafter locked in any selected angularposition of adjust- T116111. It will be understood of course that thevarious earns 34 will be angularly adjusted on the cam shaft 233 so thatthe rise portion of each cam portion will, through the medium of arocker arm 33, effect lowering of its respective pump plunger 24 duringthe time that the intake valve of the engine cylinder which is beingserved by the particular cam and plunger is in its opening cycle, andthat the decline portion of the cam will be encountered by the camfollower roller 178 after the intake valve has become closed. As bestseen in FIGS. 4 and 6, the cam shaft 233 extends longitudinally throughthe casing 43 and has its rear end region reduced as at 235 andsupported in a roller bearing 236 carried by the rear end wall 5% of thecasing 43. The front end region of the cam shaft 236 is similarlyreduced as at 237 and is supported in a roller bearing assembly 238carried by the front end wall 48 and held in position thereon by aretainer plate 240 which is removably se- 17 are operatively installedwithin these vertical bores and operate in a manner that will bedescribed subsequently. The thickened portion '70 of the side wall 44;of the casing ltl is formed with an outwardly facing rectangular recess76 of relatively large proportions, this recess being separated from theoperating chamber 7% provided within the casing 40 by means of arelatively thin wall section 80. The recess 76, in combination with agenerally rectangular cup-shape closure plate 82 defines the previouslymentioned fuel supply reservoir 14. The closure plate '82 has an openflanged rim 84 which is bolted as at 86 to the thickened wall portions70 exteriorly thereof. A suitable gasket 83 elfects a seal for thereservoir 14. A fuel feed opening 94) (FIGS. 5 and 7) is provided with asuitable fitting 92 by means of which a fuel line, fragmentarily shownat 94 may be connected to the reservoir 14, this fuel line leading froma suitable source of fuel such as the gasoline of diesel oil tank (notshown) of the vehicle. A primary cup assembly 95 communicates throughthe plate 32 with the reservoir 14.

The Pump Assemblies The various pump assemblies 17 are identical inconstruction, and therefore it is believed that a description of one ofthem will suflice for them all. There is one pump assembly for each fuelinjection nozzle 16 and each pump assembly comprises an outer guidesleeve 1% (FIGS. 2 and 3) which is press-fitted or otherwise securedwithin its respective vertical bore 74 with its upper end extendingupwardly as at 14M above the edge 71. Each vertical bore 74 intersectsthe recess 76 so that the vertical wall face 192 of the recess is cutback a slight distance with the medial region of the guide sleeve 1Wtraversing the recess and being completely surrounded by the fuel withinthe reservoir 14. Each pump assembly further includes a tubular valveseat-forming member which is telescopically received within the lowerend of the guide sleeve Mill and which is provided with an enlarged heador flange 1% at its lower end defining a valve seat 1%. The bore 74 isreduced as at Hit where it passes through the depending portion 72 ofthe thickened part 70 of the wall 44 thus affording an upwardly facingshoulder 112, and between which shoulder and the lower rim of the guidesleeve 1% the head like is fixedly clamped.

The valve seat 108 is designed for cooperation with a conical face 114provided on the valve 32. The valve 32 is normally maintained in itsclosed position on the seat 108 by means of the previously mentionedcompression spring which encircles a valve stem 118 and bears at itslower end against the bottom wall of a socket 120 provided in a sealingplug 122 forming a part of the fitting assembly 42. The character of thevarious fitting assemblies will be made clear subsequently.

The valve element 32 is provided with a pilot stem 124 having a bore 126extending therethrough axially thereof. The axial bore 126 intersects atransverse bore 28 to permit passage of fuel from the pressure chamber28 through the valve and into the reduced bore lllll when the valve 32is moved from its seat 108.

Each pump plunger 24 includes a head portion 130 which is slidablewithin the guide sleeve Ni), and it also includes a reduced stem portion132 which is slidable within the seat-forming tube 194. A compressionspring 134 surrounds the stem portion 132 of the plunger 24 and bears atits lower end against the upper end of the seat-forming tube 1G4 and atits upper end against the annulus provided at the lower end of the headportion 130 of the plunger 24. The plunger 24 is thus normally urgedupwardly within the guide sleeve toward a fully retracted position.

The previously mentioned inlet opening 26 exists by virtue of theprovision of a series of radially disposed registering holes provided inthe guide sleeve ltltl and tube 1&4 respectively, these two holes movinginto exact alignment when the two parts are telescopically assembled oneach other to provide the inlet opening 26 (FIG. 5). The inlet opening26 thus establishes communication between the reservoir 14 and thepressure chamber 28 within the pump.

(The Pump Fittings) The fittings 22 for the various pump assemblies 17utilize conventional or slightly modified automotive fitting hardware.The sealing plugs 122 have elongated shank portions 1% which arethreadedly received as at 142 in the reduced portions of the bores 74.The bottom of the socket in each plug 122 is drilled as at 144 toprovide a channel which communicates with the central bore 146 in anipple member 148 which surrounds the shank and which is clamped againstthe underneath base of the depending portion 72 of the casing 40 bymeans of a sealing plug 122. The bore 138 communicates with the tubing12 and the latter is clamped to nipple member by means of a threadedcollar 150.

(Operation of the Pumping Instrumentalities) In the operation of thevarious pump assemblies, the plunger 24 of each assembly is normallymaintained in its retracted position under the influence of the spring134, this elevated or fully retracted position of the plunger beingillustrated in FIG. 5. As will be described subsequently, the extent towhich the plunger 130 may be retracted is a function of the elevation ofthe vertically movable rocker arm shaft 36. For example, in FIG. 2, theshaft 36 has, under the influence of the lever arm 33, been shifted to alower position than that in which it is shown in FIG. 5 so that thefully retracted position of the plunger 24 is not as high a position asis the case in connection with the disclosure of FIG. 5.

Considering, for the time being, only the operation of the plunger 24with the rocker arm setting of FIG. 5, it will be seen thatreciprocation of the plunger 24 will carry the same from its full lineretracted position to its dotted line advanced position wherein thelower end of the plunger 24 moves past the cut-oif opening 26. Uponrotation of the cam 34, the rocker arm 33 will cause the plunger 24 toreciprocate between its full and dotted line position as shown in FIG. 5and, because the cam 34 is a fixed cam in the sense that itseccentricity cannot be changed, the amplitude of the stroke of theplunger 24 will be unvaried and the plunger will reciprocate at arelatively high level with respect to the guide sleeve 100 andsear-forming tube 194. Upon each descent of the plunger 24 the lower endof the latter will be carried past the cut-off opening 26 only a slightdistance so that a small volume of fluid will be pressurized in thechamber 28 and forced past the normally closed valve 32 against theaction of the compression spring 30. Since a solid column of fluidexists in the pressurizing chamber 28, reduced bore lit and tubing 12, alimited amount of fuel will be forced through the injection device 16and into the intake manifold during each stroke of the plunger 24. Theshaft 36 is capable of vertical adjustment as will be describedpresently between the elevated limit wherein only suflicient fuel ispassed through the injection device 16 to maintain the engine at idlingspeed, and a lowered position wherein a maximum amount of fuel is forcedthrough the injection device 16 during each downward stroke of theplunger 24.

Considering now the disclosure of FIG. 2, the shaft 36 which supportsthe various rocker arms 33 is shown in a lowered position and the fullyretracted position of the plunger 24 is shown in full lines. The rockerarm now operates from the fixed cam 34 in such a manner that it has thesame amplitude of oscillation as when the shaft 36 is in the elevatedposition of FIG. 5, the plunger 24 will also reciprocate with the sameamplitude of displacement, but this plunger 24 will operate within thesleeve 1% and tube 104 at a lower elevation, so to speak,

cured to the wall 48 by screws 242. The front reduced end 237 of theshaft 230 carries a gear 244 exteriorly of the casing 240* and this gearmeshes with the timing gear 246 of the engine. The entire fuel injectionassembly 10, including the exterior gear 244, are shown in FIG. 1 asbeing enclosed by an outer removable box or casing 247.

The Lubrication System In order to lubricate the moving parts within thechamber 78 provided by the casing 4d, a splash system of lubrication isprovided whereby a suitable liquid lubricant which is maintained in theform of a pool 2% is maintained in constant agitation within the chamberand is caused to drip from the two previously mentioned ribs 6 5 and s2.so as to supply lubricant to localized regions of the mechanism whichrequire a more thorough lubrication than other regions thereof.Accordingly, a pair of centrifugal lubricant slinger wheels 2534 (FIGS.5 and 6) are mounted in spaced relationship within the chamber 78 on ashaft 256 which extends longitudinally across the casing and has itsopposite ends supported in bearing sleeves 25S rcmovably secured in theends walls 48 and 50 by means of retainer plates 269. The shaft 256carries a gear 262 which meshes with a similar gear 264 mounted on thecam shaft 23% so that the shaft 256, and consequently the slinger wheels254 will be driven from the cam shaft 236. Each slinger wheel 254 isprovided with notches 2&6 in the periphery thereof to enhance theagitation of the lubricant 25% so that a greater quantity of lubricantwill adhere to these wheels and be flung outwardly under the influenceof centrifugal force against all of the various moving parts within thechamber 73. The rib overlies and is substantially parallel to the rockerarrn shaft 36 so that lubricant collecting on the underneath face of thecover plate 52 will drip from this rib directly onto the medial regionsof the rocker arms 33 and thus find its way to the bearing surfacesbetween these rocker arms and the shaft 36. Similarly the rib 62 isdisposed above and extends parallel to the cam shaft 236 so thatlubricant will drip directly onto the various cams 34 and cam followerrollers 178 to adequately lubricate them. The gear 262 projects into thepool of lubricant 250 and will thus pick up lubricant from the pool andtransmit the same to the gear 264. Other moving parts within the casing78 such as the actuating finger 212 and bifurcated end 214 of the leverarm 160 will receive adequate lubrication by the application thereto oflubricant flung from the Wheels 254.

Assembly, lllaintenance and Special Considerations Referring nowspecifically to FIG. 5, it is contemplated that due to the maintenanceof small tolerances during the manufacture of the various moving partsof each pump assembly li', there will be practically no leakage of fuelpast the pressurizing or operating end of the plunger 24 to the annulusexisting between the reduced portion 132 of the plunger and the tube Hi4when the fuel injection apparatus is first put into service and during along period of time thereafter. However, after a period of time, theremay be slight wear between the two sliding parts so that a small amountof fuel leakage will take place. Although this amount of leakage Will beextremely small, in the absence of any provision for overflow of fuelfrom the annulus existing between the reduced portion 132 of the plunger24 and the guide sleeve 1%, this annulus is likely, in time, to becomefilled with fuel, thus establishing a solid and incompressible liquidcolumn which ordinarily would prevent descent of the plunger 24 andpossibly result in damage or breakage to the various moving parts of theapparatus. To relieve such a condition, each guide sleeve 1% has formedtherein a small aperture 270- which registers with a similar aperture272. formed in the thickened wall portion 70 of the end wall 44 so thatfluid may escape from the annulus surrounding the reduced end 132 of theplunger 24 into the chamber 78 and mingle with the pool of liquidlubricant 258* in this chamber. To prevent the turbulent lubricant inthe chamber 278 from entering the annulus, a series of spring fingers274 are provided on a flat spring strip 276 which is held in positionagainst the inside face 278 of the thickened portion 74} by means of aclamping bolt assembly 280. The spring fingers 27d depend from the strip276 and each finger is adapted to cover one of the holes 272 provided inthe thickened portion 79 of the rear end wall 44 so that it will operatein the manner of a check valve to allow pressurized fluid in the annulussurrounding the reduced end 132 of the plunger 24 to pass outwardly andinto the chamber '73 while at the same time preventing return passage offluid through the hole 272. It will be appreciated that extremely minutequantities of entrapped fuel are involved so that dilution of thelubricant 250 with fuel is not appreciable. Any fuel which does passinto the chamber 73 from the annulus surrounding the plunger stem 132 isitself a mild lubricant so that the efficiency of the 1ubricant in thepool 25% is at no time endangered.

The various internal operating parts of the fuel injection assembly 10of the present invention are readily accessible by virtue of theremovable cover plate 52 and the removable reservoir-forming closureplate 32. With the cover plate 52 removed the adjusting screws and locknuts 182 are accessible for purposes of adjustment, as also are the setscrews 23% by means of which the angularity of the various cams 34relative to the cam shaft 230 may be altered. The fuel injectionassembly may, by simple adjustment, be rendered suitable for use inconnection with motors having different fuel combustion or firing ordersby properly setting the angularity of the various cams 34 any desiredfiring order may be accommodated.

Plunger removal and replacement may readily be effected by loosening theclamping screw Zilt) (FIGS. 4 and 5) so that the foot member 1% is freeupon the shaft whereupon this latter shaft is capable of unlimitedturning movement so that the fingers 212 of the collars 210 may leavethe bifurcations 214 at the distal end of the lever arms 166 and alsothe entire U-shaped frame assembly including the lever arms 169 andshaft 36 to be elevated to the dotted line position wherein it isillustrated in FIG. 5. With this assembly thus elevated, the upper endsof the various plungers 24 are accessible and may be pulled verticallyoutwardly from the guide sleeves 100 for purposes of inspection,replacement of the springs 134 or plungers 24.

From the above description it is thought that the construction andoperation of the herein described fuel injection system will be readilyapparent. The invention is not to be limited to the exact arrangement ofparts shown in the accompanying drawings or described in thisspecification, since various changes in the details of construction maybe resorted to without departing from the spirit of the invention. Onlyinsofar as the invention has particularly been pointed out in theaccompanying claims is the same to be limited.

Having thus described the invention which I claim as new and desire tosecure by Letters Patent is:

1. Liquid fuel injection apparatus comprising in combination, a casingstructure defining a fuel reservoir, a plurality of injection pumpassemblies, each pump assembly including a tubular vertically disposedpump body providing a pumping bore, there being a fuel inlet cut-offopening in the wall of said pump body, the various pump bodies being atleast partially submerged within the liquid fuel in the reservoir withsaid cut-off openings in direct communication with the liquid fuel, apump plunger reciprocable in said bore and having an end thereof movablepast said cut-off opening in sealing relationship with respect thereto,the portion of the bore forwardly of the cut-01f opening constituting afuel pressurizing and displacement chamber, said casing structure alsodefining an internal operating chamber, a vertical wall separating saidreservoir from the operating chamber, a pair of lever arms pivotedwithin the operating chamber for limited swinging movement about ahorizontal axis, a horizontal shaft extending between said lever armsand capable of limited vertical displacements upon movement of the leverarms, a series of rocker arms, one for each plunger, mounted medially oftheir ends on said shaft, a cam shaft extending across the chamber andparallel to said shaft, one end of each rocker being designed forengagement with one of said plungers and the other end being designedfor engagement with the cam shaft, a rock shaft extending across thechamber and parallel to the cam shaft, the distal end of each lever armbeing provided with a bifurcation, a finger on said rock shaft andprojecting into respective bifurcations on the lever arm, and anoperating lever connected to said rock shaft and disposed exteriorly ofthe chamber.

2. Liquid fuel injection apparatus comprising in combination, a casingstructure defining a fuel reservoir, a plurality of injection pumpassemblies, each pump assembly including a tubular pump body providing apumping bore, there being a fuel inlet cut-off opening in the Wall ofsaid pump body, the various pump bodies being at least partiallysubmerged within the liquid fuel in the reservoir with said cut-offopenings in direct communication with the liquid fuel, a pump plungerreciprocable in said here and having an end thereof movable past saidcut-off opening in sealing relationship with respect thereto, theportion of the bore forwardly of the cut-off opening constituting a fuelpressurizing and displacement chamber, said casing structure alsodefining an internal operating chamber and lubricant reservoir, avertical wall separating said fuel reservoir from the operating chamber,a rocker arm for each plunger and having one end thereof designed foroperative engagement with an end of the plunger, a rocker arm shaftwithin said operating chamber and common to all of the rocker arms andon which the arms are pivotally mounted medially of their ends, a camshaft within said operating chamber and having cams thereon designed forengagement with the other ends of the rocker arms, an additional shaftextending across said operating chamber below the level of said rockerarm and cam shafts, a plurality of slinger wheels mounted on saidadditional shaft, means operatively connecting said cam shaft andadditional shaft in driving relationship, a pool of lubricant withinsaid operating chamber and lubricant reservoir, manually operable means,operable at will for shifting the position of said rocker arm shaft inthe general direction of movement of the plimgers to simultaneously varythe position of the range in which the plungers reciprocate in theirrespective pumping bores, a removable cover plate for said operatingchamber and lubricant reservoir, and a pair of lubricant collecting anddistributing ribs formed on the underneath side of said cover plate, oneof said ribs being substantially coextensive with, parallel to and invertical register with said rocker arm shaft for drip lubrication of thelatter and the rocker arms thereon, the other rib being substantiallycoextensive with, parallel to and in vertical register with said camshaft for drip lubrication thereof and of the cams thereon.

3. Liquid fuel injection apparatus comprising a casing having a bottomwall, upstanding side walls, a front end wall, and a rear end wall, acover plate removably closing the upper end of said casing and definingwith the various Walls thereof a closed internal chamber, one of saidside walls being formed with a relatively thick wall portion below theupper edge thereof and defining an upwardly facing ledge below thelevelof said cover plate, said relatively thick wall portion being formedwith a series of vertical bores therein, closure plate secured to theouter face of said one side wall and, in combination therewith 12defining a fuel reservoir exteriorly of the chamber, said bores normallyestablishing communication between said reservoir and chamber throughsaid ledge, there being a fuel inlet cut-oif passage in the wall of eachbore establishing communication between the reservoir and the interiorof the bore, the portion of the bore below the cut off passageconstituting a fuel pressurizingand displacement chamber, a pump plungerreciprocable in each bore and having an end thereof movable past thecut-off passage, a fuel line establishing communication between saidchamber and one of the fuel injector nozzles, a check valve disposed insaid fuel line, a rocker arm for each plunger within the chamber, saidrocker arm having one end in operative engagement with the plunger abovethe ledge, a rocker arm shaft in said chamber on which all of the rockerarms are pivotally mounted, a cam shaft in the chamber and having camsthereon designed for engagement with the outer ends of the rocker arms,said relatively thick wall portion being provided with a series of drainpassages above the level of the cut-off passages and establishingcommunication between said bores and said internal chamber for the flowof leakage fuel from the reservoir into the chamber, and manual meansoperable at will for shifting the position of the vertical range inwhich the plungers reciprocate in their respective bores.

4. Liquid fuel injection apparatus comprising a casing having a bottomwall, upstanding side walls, a front end wall, and a rear end wall, acover plate removably closing the upper end of said casing and definingwith the various walls thereof a closed internal chamber, one of saidside walls being formed with a relatively thick wall portion below theupper edge thereof and defining an upwardly facing ledge below the levelof said cover plate, said relatively thick wall portion being formedwith a series of vertical bores therein, a closure plate secured to theouter face of said one side wall and, in combination therewith defininga fuel reservoir exteriorly of the chamber, said bores normallyestablishing communication between said reservoir and chamber throughsaid ledge, there being a fuel inlet cut-01f passage in the wall of eachbore establishing communication between the reservoir and the interiorof the bore, the portion of the bore below the cut off openingconstituting a fuel pressurizing and displacement chamber, a pumpplunger reciprocable in each bore and having an end thereof movable pastthe cut-off opening, spring means normally urging said plunger upwardlyin said bore, a pair of lever arms within said casing and having theirproximate ends pivoted to the end walls of said casing in the vicinityof the other side wall for vertical swinging movements about a commonhorizontal axis, a rocker-supporting shaft rigidly connected to thedistal ends of said lever arms, a cam shaft extending across the chamberand parallel to said rocker-supporting shaft, a rocker arm for eachplunger pivoted to said shaft and having one end operatively engagingthe upper end of the plunger above said ledge and having its other endoperatively engaging said cam shaft, a rock shaft extending across thechamber and parallel to the rocker-supporting shaft, the distal ends ofsaid lever arms being bifurcated, fingers on said rock shaft andextending and confined between the bifurcations of the lever armsrespectively, a limit stop abutment on said casing, a cooperating limitstop abutment on said rock shaft to limit the turning movement of therock shaft in one direction, means for disabling the cooperation betweensaid limit stops whereby said rock shaft may be turned to such an extentthat the fingers on the rock shaft are released from their confinementbetween said bifurcations so that the lever arms, together with saidrocker-supporting shaft and the rocker arms thereon may be swungvertically upwardly about said common horizontal axis to anout-of-the-way position wherein the upper ends of the plungers areaccessible for withdrawal of the plungers from said bores, and amanually operable lever mounted on said rock shaft for 13 applyingturning movements to the latter in either direction.

References Cited in the file of this patent UNITED STATES PATENTS1,076,436 Lemp Oct. 21, 1913 1,730,116 Brockway Oct. 1, 1929 1,871,872Baur Aug. 16, 1932 2,083,021 Hegn June 8, 1937 2,114,565 Kovach Apr. 19,1938 14 Maniscalco Aug. 15, 1939 Simons Oct. 17, 1939 Widmer Dec. 12,1950 Edwards July 10, 1951 Voit et a1 Mar. 27, 1956 Brunner May 29, 1956Seifert et a1 Apr. 22, 1958 FOREIGN PATENTS Great Britain Dec. 22, 1930France Jan. 21, 1929

